Shadowing Practice: Feedback Mechanisms - Your body’s control Systems - Physiology - Learn English Speaking with Video

Creating lesson...
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What's up nerds?
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How are you today?
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Today's topic is control systems of your body, the amazing physiology, how your body stays alive.
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So, let's get started.
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But first, let's get this example.
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You have your thyroid gland taking orders from the pituitary gland to secrete thyroid hormone in the bloodstream.
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If there is an excess amount of thyroid hormone in the bloodstream, it will produce something we call negative feedback.
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It will tell the thyroid, stop what you're doing, we already have enough.
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And it will tell the pituitary, this is your pituitary, not your testicles,
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please stop producing TSH to stimulate this thyroid hormone production, we already have enough.
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Your body has thousands of control systems.
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Your body is a control freak.
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They keep your body alive.
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A significant change in your internal environment, also known as the extracellular fluid, can lead to your death.
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Life needs balance.
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Life is only possible within a narrow range.
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For instance, your body temperature at change of greater than 7 degrees Celsius
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or 11 degrees Fahrenheit can literally put you to death.
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If you don't get it, let's get an example.
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Regulation of oxygen and carbon dioxide in the extracellular fluid.
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Here is your blood vessel.
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It has red blood cells and they have hemoglobin.
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Hemoglobin carries oxygen.
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Oxygen is given to the tissue, but when the oxygen in the tissue is very abundant, they will tell the hemoglobin, thank you, we have enough oxygen.
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So the oxygen stops flowing from hemoglobin to the cell because hemoglobin has a high affinity to oxygen.
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It really loves oxygen too much.
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But on the other hand, if you have lots of carbon dioxide in the tissue, the cells will handle them to the hemoglobin.
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Please take care of this carbon dioxide
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and it will carry it to the lungs your lungs will exhale the carbon dioxide out.
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Okay, when the CO2 is like abundant in your blood, the brainstem is stimulated.
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So, you will breathe rapidly and deeply to get rid of this CO2.
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Very cool.
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By the way, this is called oxygen buffering function of hemoglobin, which is indeed astonishing.
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Now, let's turn our attention to the story of your blood pressure regulation.
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Let's suppose that you are having increased of your blood pressure.
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This will stretch your arteries.
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In your arterial walls, especially the aortic arch and the bifurcation of the carotid artery, you have some stuff called baroreceptors.
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So, receptors are easy to understand.
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Okay, what about baro?
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You remember in physics the barometer, okay, pressure meter.
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So baro means pressure.
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They sense pressure.
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So when you stretch these arteries, they will sense this pressure.
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They will give nerve impulses to the medulla of your brainstem.
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This nerve impulses or this vasomotor center will respond by dilating your blood vessels and decreasing the pumping activity of your heart,
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which will lead to decrease your blood pressure and back to normal.
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Very well done.
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On the other hand, if you have low blood pressure, stretches of the arterial wall will decrease, which will lead to less stimulation of baroreceptors,
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loss of inhibition of the vasomotor center, loss of inhibition equals kind of stimulation.
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So will lead to constriction of your blood vessels and increase pumping activity of your heart.
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They will raise your blood pressure and back to normal.
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Amazing!
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To get an idea about the tight regulation, take calcium for example.
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Very low calcium and you get titanic convulgence.
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Very high calcium and your heart will stop.
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Potassium, very high potassium your heart suffers.
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Very low potassium can lead to muscle problems or heart problems.
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Glucose, low glucose seizure.
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high glucose you can end up in coma such as in hyperosmolar non-ketotic coma and stuff like that also diabetic ketoacidosis.
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The concept of negative feedback is truly amazing.
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So high carbon dioxide you will breathe rapidly and deeply in response.
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This is called hyperventilation.
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This will lead to exhaling CO2 and reducing its amount back to normal.
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Why is this negative feedback?
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Because the result is opposite to the initiating stimulus.
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This is called negative.
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The increased CO2 started the events that will lead to its reduction.
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This is called negative feedback.
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On the other hand, low CO2, you will breathe slowly, called hypoventilation, to make the CO2 build up.
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This is also negative feedback.
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Hey, but wait, this CO2 is increasing.
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Yes, still negative because the result is opposite to the initiating stimulus.
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So we call this negative feedback.
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Negative feedback is cool, but positive feedback sometimes can lead to death.
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Oh, really?
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Yes.
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Normally you have five liters being pumped by your blood in every minute.
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Let's say that you are an idiot texting while crossing the street
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and you got hit by a car and you bled 2 liters of blood.
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Your heart will pump 3 liters instead of 5 per minute, which will lead to less blood going to the coronary arteries which feed the heart itself.
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This will lead to decreased pumping activity of the heart the
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heart pumps less blood less blood goes to the coronaries
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and you are in a vicious cycle until you die okay stop texting
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while crossing the street but on the other hand
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if you let only one liter okay negative feedback will happen yes your heart will pump less blood
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but this negative feedback will kick in to override the positive feedback
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and you can live so positive feedback in the first example can lead to death.
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So you're saying that positive feedback is always bad?
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No, no, no, no. It can be beneficial.
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For instance, when you bleed, activation of the clotting cascade will lead to activation of other enzymes in the adjacent vessels.
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They activate the cascade, activate the cascade of other tissues, activate the cascade, and you stop bleeding.
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Also, and uterine contractions during child labor.
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The mommy pushes the baby.
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Okay.
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These are called uterine contractions.
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They push the baby to the cervix.
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Stretch of the cervix will lead to more contractions.
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More contractions, more pushing, more contractions, more pushing, more dilation of the cervix, more contractions, and so forth.
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This is called a positive feedback, and it has a very beneficial result.
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The baby is born.
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Woo-hoo!
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That's it for today.
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In the next video, we'll talk about the human cell.
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So don't forget to subscribe and follow me on Facebook.
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I have 101 questions on Facebook until the end of this year.
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Also, Twitter, SoundCloud, Instagram.
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And don't forget to support me on Patreon.
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And thank you so much for watching.
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This is me, the Coast Perfectionelis.
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Be safe, stay happy, and study hard.

Vocabulary and speaking notes for this lesson

This C1 speaking lesson is built on the video “Feedback Mechanisms - Your body’s control Systems - Physiology”. The speaker keeps coming back to these words: blood, feedback, lead, negative, oxygen. This video has 110 sentences and 1108 words to shadow. The speech runs for 8:09. The speaker talks at a steady 136 words per minute, a comfortable pace for shadowing. Only 78% of the words are among the 3,000 most common in English, so the vocabulary is demanding.

Key vocabulary in this video

The 15 most advanced words in the video, with pronunciation and meaning:

WordPronunciationMeaning
hemoglobin noun/ˌhimoʊˈɡloʊbɪn/The iron-containing substance in red blood cells that transports oxygen from the lungs to the rest of the body; it consists of a protein (globulin), and haem…
contraction noun/kənˈtɹækʃ(ə)n/An act of incurring debt; also (generally), an act of acquiring something (generally negative).
thyroid adjective/ˈθaɪ.ɹɔɪd/Of, relating to, or being the thyroid cartilage.
dioxide noun/daɪˈɑksaɪd/Any oxide containing two oxygen atoms in each molecule.
cascade noun/kæsˈkeɪd/A waterfall or series of small waterfalls.
artery noun/ˈɑɹ.təɹ.i/Any of the muscular- and elastic-walled blood vessels forming part of the circulation system by which blood is conveyed away from the heart regardless of its…
cervix noun/ˈsɝ.vɪks/The neck.
pituitary adjective/pɪˈtuɪˌtɛɹi/Of or relating to the pituitary gland.
potassium noun/pəˈtæsiəm/A soft, waxy, silvery reactive metal that is never found unbound in nature; an element with atomic number 19 and atomic weight of 39.0983.
bleed verb/ˈbliːd/To shed blood through an injured blood vessel.
glucose noun/ˈɡluː.kəʊz/A simple monosaccharide (sugar) with a molecular formula of C₆H₁₂O₆; a principle source of energy for cellular metabolism.
activate verb/ˈæktɪˌveɪt/To encourage development or induce increased activity; to stimulate.
hormone noun/ˈhoɹmoʊn/Any substance produced by one tissue and conveyed by the bloodstream to another to effect physiological activity.
calcium noun/ˈkælsi.əm/The chemical element (symbol Ca) with atomic number 20: a soft, silvery-white alkaline earth metal which occurs naturally as carbonate in limestone and as…
arterial adjectiveOf or relating to an artery.

Phrasal verbs you will hear

WordMeaning
build up verbTo erect; to construct.

Sentences worth repeating

Short, complete lines from the video that you can reuse in everyday conversation:

  • How are you today?
  • If you don't get it, let's get an example.
  • So you're saying that positive feedback is always bad?

Grammar in this video

The structures the speaker uses most, with the exact words from the video:

StructureIn the video
Passive voice be + past participle — the focus is on what happens, not who does itis given · is stimulated · is called
Relative clauses who / which + clause — extra information about a person or thinghemoglobin, which is · decrease, which will · minute, which will

Pronunciation to watch

The speaker uses 6 contractions and reduced forms, such as don't, you're, we'll. Say them the short way, as you hear them.

  • The “sh” and “zh” sounds: contraction /kənˈtɹækʃ(ə)n/, inhibition /ɪnhɪˈbɪʃən/, stimulation /stɪm.jʊˈleɪ.ʃən/, initiate /ɪˈnɪʃ.i.eɪt/, activation /ˌæktəˈveɪʃən/
  • Long words — get the stress right: hemoglobin /ˌhimoʊˈɡloʊbɪn/, pituitary /pɪˈtuɪˌtɛɹi/, coronary /ˈkɔɹənɛɹi/, inhibition /ɪnhɪˈbɪʃən/, stimulation /stɪm.jʊˈleɪ.ʃən/

How to practise with this video

  1. Listen to the whole video once without speaking and note the words you do not know.
  2. Shadow it sentence by sentence at normal speed, repeating each one until your rhythm matches the speaker.
  3. Record yourself and compare with the original, paying attention to words like hemoglobin, contraction, thyroid.

What is the Shadowing Technique?

Shadowing is a science-backed language learning technique originally developed for professional interpreter training and popularized by polyglot Dr. Alexander Arguelles. The method is simple but powerful: you listen to native English audio and immediately repeat it out loud — like a shadow following the speaker with just a 1–2 second delay. Unlike passive listening or grammar drills, shadowing forces your brain and mouth muscles to simultaneously process and reproduce real speech patterns. Research shows it significantly improves pronunciation accuracy, intonation, rhythm, connected speech, listening comprehension, and speaking fluency — making it one of the most effective methods for IELTS Speaking preparation and real-world English communication.

Shadowing technique: read the full step-by-step guide →